Automated weaning from mechanical ventilation

Abstract

Mechanical ventilation (MV) is one of the lifesaving techniques applied to critically ill patients at bedside. However, some complications, such as ventilator-induced lung injury and ventilator-associated pneumonia, may occur in a patient undertaking MV and are often related to the duration of MV. Some written protocols have been proposed to reduce the risk of such complications, but they can be time consuming, leading to fluctuation in protocol implementation and compliance. Moreover, written instructions tend to be general and thus cannot cover all possible scenarios, resulting in variable interpretation of the protocol. To overcome these limiting factors, protocols have been computerized and there is convincing evidence in the literature showing that computerized protocols benefit management of the process and reduce the time a patient spends under MV. QuickWean is a computer-aided weaning protocol implemented on the Hamilton S1 ventilator (Hamilton Medical AG, Bonaduz, Switzerland), which guides the patient through the weaning process without requiring any intervention by the treating physician. The fully-automated ventilation mode is INTELLiVENT^®-ASV (Hamilton Medical AG), which is set according to the patient’s respiratory mechanics, patient-ventilator interaction, peripheral oxygen saturation (SpO₂) and pulmonary end-tidal carbon dioxide (PetCO₂). The INTELLiVENT^®-ASV mode sets automatically each minute to provide accurate ventilation, pressure support, fraction of inspired oxygen and positive end-expiratory pressure based on the patient’s needs. QuickWean can be pre-set to match the established weaning policy of an intensive care unit as well as being customized to a patient’s needs. It provides a progressive reduction of respiratory support, and guides the patient through the spontaneous breathing trial (SBT). At the end of the SBT, the ventilator re-starts the previous ventilation support and provides a report of the successful SBT. During all phases, PetCO₂, SpO₂ and all breathing parameters are monitored. This new automated weaning tool may improve the safety and effectiveness of an SBT, reducing the time spent in the process of weaning and providing a lower workload for the treating physician.

Keywords: Automated ventilation, Automated weaning, Weaning from artificial ventilation, Weaning protocol, QuickWean

Core tip: Weaning from mechanical ventilation is a crucial point during respiratory therapy and most intensive care units have developed human-based protocols to wean the patient. Newer ventilators have implemented a computer-aided weaning protocol, and the QuickWean application may be the most complete because it can drive the patient automatically from total passivity to readiness to wean. A key feature of the full computer-driven process is the safeness of the procedure, ensured by the patient always being under control in terms of peripheral oxygen saturation, pulmonary end-tidal carbon dioxide and respiratory fatigue, and improving upon the discontinuous human-driven process.